ConfigServer Community Forum

Hi i have a dedicated server CentOS 5,9 with WHM 11.36.0.11 and in the last update CSF v6.00 at 2 weeks agoo become a problem to me.

This server only have one site "vbulletin forum", and after this upgrade my users say the site is extrem slow.

After a quick tests with a browser cleaned with no cache i can duplicate the problem, and the page sometimes takes 20 secounds to open and other times dont open say problem cant find the page or DNS.
I disabled the firewall and the page load in 3 secounds, after turned on same problem with a clean browser, with a browser i already opened the site the problem is not visivle but its there but the cache help.

The server have a Load Average: 0.80 0.70 0.56 same load if is on or off the CSF.

There is some log so i can try to understand where is the problem?

I find what trigered the problem in the Iptables Log:

Mar 12 14:28:19 serverxxxx kernel: Firewall: *SYNFLOOD Blocked* IN=eth0 OUT= MAC=xx:xx:6f:xx:65:62:00:04:96:36:xx:ed:08:xx SRC=xxx.251.x00.xx DST=xx9.xx3.111.xx LEN=48 TOS=0x00 PREC=0x00 TTL=120 ID=29235 DF PROTO=TCP SPT=2699 DPT=2086 WINDOW=65535 RES=0x00 SYN URGP=0

So i have checked my firewall configuration about SYNFLOOD and i have this:

SYNFLOOD = 1
SYNFLOOD_RATE = 100/s
SYNFLOOD_BURST = 150

After disable the "SYNFLOOD = 0", the problem go away, so what is the right parameters to insert here?